<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        div {
            width: 100px;
            height: 100px;
            background-color: #00FFFF;
        }
    </style>
</head>
<body>
<div hidden></div>
<input type="hidden" placeholder="隐藏的表单元素">
<script>
    let div1 = document.querySelector("div");
    div1.hidden = false;
</script>
</body>
</html>